Phosphoric acid production gypsum filtration flocculant pre-dilution (make down) with post-filtration phosphoric acid
AssigneeNalco Company
InventorsRonald V. Davis, Wayne L. Moss, Michael G. Strominger, Randon Renzello, Thomas A. Faigl, Daniel N. T. Hay
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Abstract
A method for minimizing the addition of water to a phosphoric acid production process is described. The method uses phosphoric acid to make down a flocculant that is added to the process in order to promote filtration or clarification of crude phosphoric acid. Preferably, the phosphoric acid is a crude, clarified phosphoric acid that is recycled from the phosphoric acid production process itself.
Claims10
A method of adding flocculant to a phosphoric acid production process which includes providing a gypsum slurry, the method comprising:
- creating a flocculant-acid substance by mixing phosphoric acid and a flocculant emulsion comprising 93 mole percent acrylamide and 7 mole percent sodium acrylate copolymer, thereby inverting the emulsion and causing a change in conformation of the copolymer;
- introducing the flocculant-acid substance into the gypsum slurry of the phosphoric acid production process.
A method of improving solids separation performance and minimizing the introduction of additional fresh water in a phosphoric acid production process which includes providing a gypsum slurry, the method comprising:
- introducing a flocculant emulsion comprising a 93 mole percent acrylamide and 7 mole percent sodium acrylate copolymer directly into phosphoric acid;
- mixing the flocculant emulsion and the phosphoric acid, thereby inverting the flocculant emulsion and causing a change in conformation of the copolymer and forming a flocculant-acid substance;
- adding the flocculant-acid substance to a gypsum slurry of the phosphoric acid production process;
- and
- separating flocculated gypsum from the gypsum slurry;
- wherein the phosphoric acid is clarified crude phosphoric acid recycled from the phosphoric acid production process;
- and
- wherein the mixing is achieved via inline blending.
A method of adding flocculant to a phosphoric acid production process which includes providing a gypsum slurry, the method comprising:
- creating a flocculant-acid substance by inverting a flocculant emulsion comprising a 93 mole percent acrylamide and 7 mole percent sodium acrylate copolymer with phosphoric acid;
- flocculating gypsum in a gypsum slurry of the phosphoric acid production process by combining the flocculant-acid substance and the gypsum slurry of the phosphoric acid production process;
- and
- separating at least a portion of the flocculated gypsum via a filtration operation.
Dependencies are inferred from the claim text.